The present invention relates generally to the field of data communication and more specifically to rights management and securing data communicated in a network.
A growing interest in streaming distribution of multimedia content over Internet Protocol (IP) networks has resulted in a growing need for key management systems. One such streaming distribution system is the Aerocast Network™ developed by Aerocast, Inc. of San Diego, Calif. As discussed with reference to FIG. 1, although the existing phase 1 Aerocast Network facilitates delivery of content, it lacks security and key management for the network.
FIG. 1 is a block diagram of a network 100 (by Aerocast) for facilitating streaming of content over a communication network.
Among other components, network 100 includes a content provider 102 for generating content intended for a consumer 116, Internet 114 through which content is streamed, and a central server 104 to which content provider 102 publishes its contents. Central server 104 contains a database 108 for storing content information, and a search engine 110 for searching database 108. Network 100 further comprises a provisioning center 106, and caching servers 112, 113 and 115.
In operation, consumer 116 wishing to access content by content provider 102, streams the content from the closest caching server, in this case, caching server. 115. In conventional systems without caching servers, consumer 116 desiring such content streams obtains content directly from content provider 102. Not only does this result in poor content quality, delays associated with inadequate bandwidth may result. By using the caching servers, network 100 avoids disadvantages associated with direct streaming of digital content from content provider 202. Caching servers 112, 113 and 115 may be local DSL (digital subscriber line) providers, for example.
Network 100 provides a further advantage. When searching for content, consumer 116 need not search any and all databases on Internet 114. All content providers (including content provider 102) on network 100 publish descriptions of their content to a single central database 108. For video content for example, such descriptions may include the movie name, actors, etc. In this manner, when content is desired, consumer 116 uses search engine 110 to search database 108. When the content is found, database 108 thereafter provides a link to content provider 202 having the desired content. Content provider 102 is then accessed by consumer 116 to access the desired content in more detail. Such details include pricing information, etc.
A mechanism is provided whereby consumer 116 provides a list of caching servers closest to it to content provider 102. In response to consumer 116's request, content provider 102 selects the appropriate caching server closest to consumer 116 for streaming the content. It should be observed, however, that in today's Aerocast network content is streamed in the clear by network 100. Disadvantageously, because it is unprotected, the content may be intercepted by an unauthorized consumer resulting in substantial losses to content providers and consumers.
Some disadvantages of network 100 are resolved by the aforementioned related patents, commonly owned and hereby incorporated by reference as if set forth in their entirety in the present specification.
Cable key management systems typically employ messages known as ECMs (entitlement control messages) and EMMs (entitlement management messages) to control access to data streams. EMMs are control messages that convey access privileges to subscriber terminals. Unlike ECMs (entitlement control messages) which are embedded in transport multiplexes and are broadcast to multiple subscribers, EMMs are sent unicast-addressed to each subscriber terminal. That is, an EMM is specific to a particular subscriber.
In many cases, however, EMMs and ECMs are delivered to set-top boxes at the end-user for evaluation. The set-top box location makes it relatively easier for unauthorized users to access and modify EMM and ECM messages. Even where location is no problem, using EMMs and ECMs for software clients can be less secure. Unlike hardware set-top boxes, software code is more readily reversed engineered to provide users with unauthorized access to content.
Therefore, there is a need to resolve one or more of the aforementioned problems, and the present invention meets this need.